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Link doesn't work, can you use Google translator instead?
 

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I have heard of this a few years back.

I have not inspected mine, because I don't know if it might be spring loaded, or if something inside will move if I remove it. If engaging the parking brake is sufficient to hold everything in place, I would check it. But until I am sure, I will leave it in place.

If I find the original thread, I will post it.
 

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Ahhhh...I can help

According to the Spanish post dated November 2009:

The bolt in question, Part # 21748-10G10, is what locks the primary pulley of the CVT to the shaft. It appears that there have been several instances of deterioration with little explanation as to the source.

The article doesn't mention any outright failure, but does indicate that an outright failure could turn into a $1400 repair. Pictures of the affected bolts, range from 10K miles to 40K miles of service. The first picture looks to me as some sort of corrosion taking place, the majority of the samples show some sort of metal farcture.

The article does show a picture of the bolt location and indicates that it can be replaced if one locke the rear wheel by applying and holding the rear brake during the operation. The specified torque is 36 N.m or 26 ft-lb, they also indicate the use of thread locker. Personally I would use Blue Loctite.

I have enclosed the spanish link to have both the translation and the pics in one post

http://foro.burgmanspain.org/viewtopic.php?f=5&t=18585

Although the translation is a true representation, I have not performed the operation myself, so proceed at your own risk.
 

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I was HOPING you'd see this thread and help, Boxermania!

Got a couple of questions for you. What caused these people to pull the bolt out and inspect it? What were there symptoms of the problem?

I have to question the credibility of the article due to their recommendation of locking the rear wheel during the procedure. I presume it is to keep anything in the drivetrain from turning, and somehow misaligning components in the CVT that would keep one from reinstalling the stopper bolt. However, the CVT is BEFORE the clutch, and if the clutch does its job the CVT will not turn even if you spin the rear wheel by hand. A lack of basic understanding about the drivetrain makes me wonder if they really understand the situation with the CVT.

http://burgmanusa.com/bkb/650+Clutch+Info

FYI, this post seems to be the one that started that article: http://foro.burgmanspain.org/viewtopic. ... 43#p183243

Also, I have looked at the Babel Fish and Google translations side by side, and the Google version is far more easier to understand.
 

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Colchicine said:
However, the CVT is BEFORE the clutch, and if the clutch does its job the CVT will not turn even if you spin the rear wheel by hand. A lack of basic understanding about the drivetrain makes me wonder if they really understand the situation with the CVT.
Just my thoughts,
I have torn down the clutch, but not the CVT, but this is what I believe is happening.

There is no load on the back end of the CVT when the engine is not running, so it can freewheel. The clutch is never completely disengaged, because of the oil in the clutch and on the plates. Although the clutch may be 95% disengaged, there will be some "stiction" of the oil on the plates, especially when cold. This would help explain why the bike is harder to push when it's cold than when it's warm. Another example would be the rear wheel turning while on the center stand at idle. The oil bath clutch acts somewhat like a torque converter in an old style automatic transmission in a car. So logically, if the rear wheel is locked, it should also prevent the part in question on the CVT, from freewheel movement. It could still move, but would have to overcome the friction of the oil in the clutch to do so.

My concern is if there is spring loaded tension anywhere else that could be released when the bolt is removed.
 

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Having looked at the primary pully from the CVT on Robin's bike I don't think there is any spring tension that your would have to worry about. All that bolt does is keep the back plate on the adjuster from moving when the stepper motor adjust the primary pully face in and out. Without it the adjuster would just spin on the shaft without moving the pully face. That is what happened to Robin's CVT when it quit shifting. The back plate was slipping past the stopper bolt so the adjuster could not change the width of the primary pully.

I also don't think having the rear brake applied would have any effect on whether or not the plate moves as you can turn it without turning the primary pully it's self. All having the brake applied would do is add a little more resistance to keep the CVT from turning. Since the primary pully is geared to the crankshaft on the engine I would think the compression of the engine would do a whole lot more to keep it from moving than any drag from the oil in the clutch.
 

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By looking closely at the pic posted by Max T and the bolt ends, it appears that the failure can be a combination of the following:

1) The necked down part of the bolt seems to engage at the very end of the extension.
2) Apparently there is some clearance between the hub and the bolt that allows for some "rocking" of the hub against the bolt head during operation.
3) The above can certainly be aggravated by the increased engine braking of the CVT design.

It would be interesting to measure the depth of the cavity the bolt fits into and compare it with the length of the bolt.
 

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The bolt does not go very far into the cavity. Robin and I are riding together today and if I can remember it I'll ask her if she still has the old primary pully out of her CVT. If so I will see if I can measure the depth.
 

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All excellent information, thank you guys! My Burgman has 85k km's on it and seeing the condition of this "stopper bolt" at various milages makes me wonder if its easy to replace it or inspect it? What would I have to do to make this happen. I certainly dont want to mess up the CVT by removing the bolt, but I'm also concerned by the cost of a repair that been explained by other BUSA members. Any input advice is appreciated.
 

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Hi Guys

Sorry but my english is not that good

I replaced the bolt this afternoon

1 put the bike on his central standard
2 blokked the rearwheel with the handbrake
3 took out the old one
4 put in the new one

I have a K7 20.000km hm........how many miles is that?
I do a lot offengine breaking with the power button

so replacing was a piece off cake

Here some pics off the bolt

[attachment=0:35e7z72q]pa1030313.jpg[/attachment:35e7z72q]
[attachment=1:35e7z72q]pa1030314.jpg[/attachment:35e7z72q]
 

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Max T said:
I have a K7 20.000kml hm........how many miles is that?
20,000 KM = 12427.42 Miles.
 

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Max T

20.000 kms = 12,400 miles

I looked at your pics very closely and by God it appears that the marls on the end of the bolt are due to "electrical arcing".
Anyone stateside that has replaced the bolt and can take/post a close-up of the damage.
 

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So this is what I have gathered from this thread.

There is this stopper bolt, it's a simple device that anchors the end of the primary pulley so that a "screw shaft" can adjust the distance between the two pulley surfaces (see pages 5-19 to 5-20 in the service manual). I agree with Buffalo that there doesn't appear to be anything that would keep one from merely swapping the bolt out.

The article says that they haven't found a correlation between wear on the end of the bolt, and mileage. I have to wonder if you shouldn't look instead at the type of driving the CVT is subjected to. The CVT doesn't have to adjust the gear ratio (thereby using the stopping bolt) very much when on the highway. In contrast the pulleys are probably in constant motion (in and out) during city driving. As far as I understand, changes in speed or throttle position beyond a certain limit illicits a change in the gear ratios. So instead of mileage alone as an indicator of wear on this bolt, I think you have to look at the usage on the CVT instead.

For a $3.50 part and five minutes worth of labor, it seems that this could be cheaper preventative maintenance than an oil change.
 

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How do you get to this bolt ?
 
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